A comparison of 108 throat and urine cultures done by conventional viral culture and by shell vial showed 84% sensitivity of the shell vial technique. During this study we also evaluated the usefulness of treating the shell vials with Dexamethasone/DMSO. We initially found that treatment with DEX/DMSO increased the number of viral foci observed and that treatment with DEX alone was insufficient. Several different monoclonal antibody stains were tested to determine which stain was the most sensitive to use. Initial comparison showed the Dupont monoclonal IFA better than the Ortho DFA which had too much background staining. We subsequently compared the Dupont IFA with Syva IFA. The latter also had problems with nonspecific staining and has since been taken off the market.